An exhaust gas-purifying catalyst includes, for example, a honeycomb substrate having a plurality of holes therein and a catalytic layer formed on the honeycomb substrate. Such an exhaust gas-purifying catalyst can be obtained by, for example, coating the honeycomb substrate with slurry containing a raw material of the catalytic layer and subsequently subjecting the coating film to drying and firing treatments.
Jpn. Pat. Appln. KOKAI Publication No. 2004-141703 describes a technique of coating the partition wall of a honeycomb substrate with slurry to form a slurry layer and then circulating air in the through-holes to remove excessive slurry. In this technique, a flow velocity control plate is provided on the end face of the honeycomb substrate on the air inflow side to prevent the flow velocity from becoming excessively high on the air inflow side when removing excessive slurry. This allows the catalyst coat layer to have the same thickness at the upstream, midstream, and downstream sections.